Number of Participants That Experienced One Grade III or Higher Unanticipated, Treatment-related Toxicity That Presents With Clinical Symptoms and Requires Medical Treatment

Number of Participants Who Experienced (a) Requirement of ≥16-hour Respiratory Assistance Per Day Continuously for ≥2 Weeks in the Absence of an Acute Reversible Illness, Excluding Perioperative Ventilation, or (b) Death

To identify candidate blood and urine biochemical markers that correlate with disease severity as determined by the Modified Hammersmith Functional Motor Scale across a range of type I, type II and type III children with Spinal Muscular Atrophy (SMA)